Résumé
A case of human brucellosis was diagnosed in France in January 2012. The investigation demonstrated that the case had been contaminated by raw milk cheese from a neighbouring dairy farm. As France has been officially free of bovine brucellosis since 2005, veterinary investigations are being conducted to determine the origin of the infection and avoid its spread among other herds. Hypotheses about the source of this infection are discussed.
In January 2012, a human case of brucellosis was diagnosed by blood culture in a district of the French Alps. The isolated strain was identified as Brucella melitensis biovar 3. The patient had presented in late November 2011 with non-specific symptoms that had been ongoing since that date. Usual at-risk exposures were investigated: recent or ancient travel in an endemic/enzootic country, consumption of raw milk or raw milk products imported from an enzootic country, professional or accidental exposure to Brucella strains in a laboratory, direct contact with animals, etc. As the patient had not had such an exposure at any point before, the case was considered to be an autochthonous case of acute brucellosis of undetermined origin.
In April 2012, brucellosis was confirmed in a dairy cow in a herd of the same district of the French Alps. The seropositive cow had aborted in late January, and a strain of Brucella melitensis biovar 3 was isolated from the milk sampled from the animal. The animal belonged to a herd 21 dairy cows, and no other animal in the herd presented with symptoms suggesting brucellosis or showed any serological reaction. Approximately 20 kg of Reblochon cheese (soft raw milk cheese) are usually produced daily on the affected farm.